Help - 2006 Sundancer 300 Port Engine Not Starting and Other Weird Electrical Stuff

[Ahoy Polloi]

I'm a noobie to boating FYI. Just purchased a used Sundancer 300 and drove it to Port Washington, NY from Patchogue, NY with no incident. Took it out a few days later with no incident. Docked the boat, plugged into shore power and left the boat on shore power overnight. Came back next morning, walk into cabin and hear a faint alarm type sound. Can't figure out where it's coming from. The CM monitor is not working so don't think it's that. When I go up to start my engines, starboard fires up no problem. When trying to start Port engine immediately get an alarm that will not go off unless I hit the crossover button next to the starboard engine button. The Halon system light goes off and the instruments for the engine go whacky. Wondering if I screwed up the batteries or smtg electrical when hooking up to shore power? Doesn't appear to be mechanical. Engine doesn't even click when trying to start. The system just goes bonkers. Also, the alarm in cabin continues to go off even with all power to boat turned off from main breaker board.

 

[Fill Ess]

When I hook up to shore power, my battery charger is only on when I turn on the AC CONVERTER breaker at the bottom of the cabin panel (120 volts section). Did you turn off both battery switches last time you left the boat? Or leave them on? You might want to go in the bilge and verify that the batteries are charged and that the charger is working. Also, before you went to start both engines, did you run the bilge blowers first?

 

[Fill Ess]

Welcome to the site BTW!

Two files you should definitely download and keep are the SR owner's manual and parts manual for the 300. If you read those over it will give you a good understanding of where most everything is located.

https://owners-resources.searayweb.com/owners-manuals-files/2006_300 Sundancer_300 Sundancer.pdf

https://s3.amazonaws.com/srweb-pvt-...550/static/parts-manuals/2006__2006-300DA.pdf

 

[Ahoy Polloi]

We did run the bilge blowers before trying to start the engines. I generally turn everything to OFF when I leave the boat so it's very possible that those battery switches were set to OFF and were never turned ON when plugged into shore power. Thank you for the links. Very helpful info.

What exactly is the procedure for plugging into shore power? Make sure that the battery switches in lower part of panel are turned ON?

 

[Fill Ess]

What exactly is the procedure for plugging into shore power? Make sure that the battery switches in lower part of panel are turned ON?

If you follow the official policy to the letter, it's on page 6.14 and 6.15 of the owners manual.

Plus where I attach the 30A cord at the dock, there is another breaker there too.

 

[cfd95]

Sounds like the battery is either not charging or is no good for the port motor.
Im guessing you have 3 batteries. 2 are wired together Starboard engine /house batteries.
The single battery is usually the port/generator battery.
CM I assume is Carbon Monoxide detector which will beep if battery is too low.